Sealing structure with barrier membrane for electronic element, display device, electronic apparatus, and fabrication method for electronic element

ABSTRACT

A sealing structure having a barrier membrane, with which the overall thickness of a display device can be reduced while ensuring sufficient barrier properties against water and oxygen so as to prevent deterioration of luminous layers. The sealing structure comprises a multi-layered resin membrane  14   b  for sealing an electronic element section  3  disposed on a substrate  2 , which is formed by alternately depositing flattening resin layers  14   c  and barriers layers  14   d  on the substrate  2 . The flattening resin layers  14   c  are formed inside a blocking region  14   a  surrounding the electronic element section  3 . A display device having the sealing structure, an electronic apparatus having the display device, and a fabrication method for the display device are also disclosed.

This is a Continuation of application Ser. No. 11/498,187, filed Aug. 3,2006, which in turn is a Division of application Ser. No. 10/341,400,filed Jan. 14, 2003, now U.S. Pat. No. 7,109,653, which claims priorityto Japanese Patent Application No. 2002-006572, filed Jan. 15, 2002. Thedisclosure of the prior applications are hereby incorporated byreference herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sealing structure for an electronicelement section such as a display element, a semiconductor circuitelement, etc., and more specifically, the present invention relates to asealing structure with a barrier membrane for a display device, anelectronic apparatus, and an electronic element section, as well as to afabrication method therefor. The description of the present inventionherein specifically pertains to an organic EL display device as anexample of preferred applications; however, the present invention is notlimited to the organic EL display device.

2. Background Art

In recent years, color display devices, which contain a plurality ofdisplay elements each of which comprises a pair of electrodes and activelayers, such as a hole-injection layer/transportation layer, a luminouslayer, etc., being sandwiched between the pair of electrodes, have beendeveloped, and specifically, organic EL (electroluminescent) displaydevices, in which organic luminous material is used for the luminouslayer, have been developed. The organic EL display device comprisesactive matrix circuits formed on a substrate made of, for example,glass, plastic, etc., electronic element sections formed on the activematrix circuits in a matrix pattern, and a “sealing can” for coveringand sealing the electronic element section.

The “sealing can” is made of glass, metal, etc., in a box shape. Thesealing structure using the “sealing can” is configured such that the“sealing can” is adhered to the periphery of the substrate usingadhesive while containing the display elements therein. The “sealingcan” also contains an inert gas such as nitrogen, argon, etc., in asealed manner along with a getter substance for absorbing water andoxygen so that permeation of water and oxygen into the display elementsare prevented, and the luminous layers are prevented from beingdeteriorated.

The overall thicknesses of conventional display devices are typically 2to 5 mm, in which approximately 1.5 mm, at least, is occupied by the“sealing can”. Because the display elements must be contained in the“sealing can” without contacting thereto, and a sufficient space forcontaining the getter substance or the like must be provided in the“sealing can”, the thickness of the sealing structure must be increasedas the sizes of the display elements increase in order to ensuresufficient strength thereof.

Moreover, because adhesive is used to adhere the “sealing can” to thesubstrate, a region for applying the adhesive must be occupied along theperiphery of the substrate, and as a result, the size of the region fordisplay, in which the display elements are arranged, is reduced withrespect to the overall size of the display device, whereby a problem isencountered in that the exterior design of the display device isconstrained when the display device is employed as a display portion ofan electronic apparatus such as a portable telephone or the like. Inaddition, an allowable space must be occupied between the region forapplying the adhesive and the region for display because the adhesivemay spread out, which leads to another problem in conventional displaydevices in that the size of a so-called frame region, i.e., a regionformed by the allowable space and the region for applying the adhesive,cannot be reduced. Furthermore, if the size of the region for applyingthe adhesive is reduced in order to enlarge the region for display, thebarrier properties of the display device against water and oxygen may bedegraded, and as a result, the luminous layers may be deteriorated(i.e., the operative lives of the luminous layers may be reduced).

Moreover, because the adhesive may not be uniformly applied to thesubstrate, or the adhesive may not function sufficiently, the region forapplying the adhesive may not be delimited from the region for displayin a manner intended, and the barrier properties of the display devicemay vary depending on location, which leads to a further problem in thatthe reliability of the display device is degraded.

Furthermore, when such a structure using a “sealing can” is employed, itis not possible to produce a top emission type display element, in whichdisplay light is emitted in the opposite direction compared with aconventional device so that a greater aperture ratio is obtainable,because the getter substance or the material forming the “sealing can”will not allow the display light to pass.

SUMMARY OF THE INVENTION

Based on the above circumstances, objects of the present invention areto provide a sealing structure with a barrier membrane for a displaydevice, with which the thickness of the display device can be reducedwhile ensuring sufficient barrier properties against water and oxygen soas to prevent deterioration of luminous layers, to provide an electronicapparatus having the display device employing such a sealing structure,and to provide a fabrication method for the display device.

In order to achieve the above objects, the present invention employs thefollowing configurations.

A sealing structure with a barrier membrane for an electronic elementsection formed or mounted on a substrate, according to the presentinvention, comprises: a multi-layered sealing membrane which is formedby overlaying at least one flattening resin layer and at least onebarrier layer, and which is deposited on the electronic element section;and a closed-loop blocking region which is formed on the substrate so asto surround the entire electronic element section or a portion of theelectronic element section while also surrounding the flattening resinlayer.

The flattening resin layer, which is the closest to the substrate amongflattening layers, may preferably be disposed so as to be adjacent tothe substrate where the electronic element section is not formed.

The electronic element section may be, more specifically, an EL(electroluminescent) display element, a semiconductor circuit element,or various circuits formed on a substrate or the like.

According to the above sealing structure with a barrier membrane for anelectronic element section, because the electronic element section issealed by the multi-layered sealing membrane which is formed byoverlaying at least one flattening resin layer and at least one barrierlayer, the multi-layered sealing membrane can be made thinner than a“sealing can” employed in a conventional sealing structure; therefore,the overall thickness of the sealing structure can be reduced whencompared with the case of the conventional sealing structure.

Moreover, because the flattening resin layer is formed, the barrierlayer formed on the flattening resin layer can be made flat, and asresult, a sealing structure with a thin membrane may be provided whichhas sufficient barrier properties, i.e., in which cracking and pin holesin the barrier layer and uneven thickness of the barrier layer can beprevented, and thus a sealing structure having a high reliability and along operative life can be provided.

In addition, because the flattening resin layer is formed inside theblocking region, the area where the flattening resin layer is formed canbe delimited by the blocking region; therefore, the size of theso-called frame region can be adjusted by the position of the blockingregion. As a result, the frame region may be made narrower than that ina conventional sealing structure so as to increase the size of thedisplay region. By delimiting the area where the flattening resin layeris formed, variation of the barrier properties depending on location canbe reduced, and reliability of sealing can be improved. Furthermore,when a plurality of display elements are fabricated in the steps ofmaking a mother substrate for fabricating a number of the displayelements at a time as shown in FIG. 21, and dividing the mothersubstrate into the individual display elements, it is possible toprevent deposition of the sealing membrane on inscribed regions alongwhich the mother substrate is to be cut, and as a result, degradation ofthe barrier properties due to damage to the sealing membrane, such asseparation from the mother substrate at a cutting operation, can beprevented.

In addition, if the flattening resin layer, which is the closest to thesubstrate among flattening layers, is disposed so as to be adjacent tothe substrate where the electronic element section is not formed,contact area between the substrate and the multi-layered sealingmembrane can be increased, whereby the barrier properties of theelectronic element section against water and oxygen can be furtherimproved.

In the sealing structure with a barrier membrane for an electronicelement section according to the present invention, the barrier layermay be formed so as to extend to the outside of the blocking region.

According to the above sealing structure with a barrier membrane for anelectronic element section, because the barrier layer is formed so as toextend to the outside of the blocking region, a wide area where thebarrier layer is formed can be ensured, whereby the barrier propertiesof the multi-layered sealing membrane can be further improved, andpermeation of water, oxygen, or the like into the electronic elementsection can be more effectively prevented.

The sealing structure with a barrier membrane for an electronic elementsection according to the present invention may further comprise anotherblocking region or other blocking regions which are disposed outside themain blocking region.

According to the above sealing structure with a barrier membrane for anelectronic element section, because a plurality of blocking regions areformed including another blocking region or other blocking regions whichare disposed outside the main blocking region, the flattening resinlayer can be reliably blocked even when the flattening resin layer ismade thick, whereby the barrier properties of the multi-layered sealingmembrane can be further improved. As a result, it becomes easy to formthe multi-layered sealing membrane by alternately depositing theflattening resin layers and the barrier layers, and thus the barrierproperties against water, oxygen, or the like can be further improved.

The sealing structure with a barrier membrane for an electronic elementsection according to the present invention may comprise a plurality offlattening resin layers, and each of the flattening resin layers may beformed inside one of the blocking regions.

According to the above sealing structure with a barrier membrane for anelectronic element section, because each of a plurality of flatteningresin layers is formed inside one of the blocking regions, theflattening resin layers can be reliably blocked by the blocking regionseven when a plurality of flattening resin layers are employed, wherebythe barrier properties of the multi-layered sealing membrane can befurther improved.

The sealing structure with a barrier membrane for an electronic elementsection according to the present invention may comprise a plurality ofbarrier layers, and each of the barrier layers may be formed so as toextend to the outside of each of the blocking regions.

According to the above sealing structure with a barrier membrane for anelectronic element section, because each of a plurality of barrierlayers is formed so as to extend to the outside of each of the blockingregions, a wide area for each of the barrier layers can be ensured,whereby the barrier properties of the multi-layered sealing membrane canbe further improved, and permeation of water, oxygen, or the like intothe electronic element section can be more effectively prevented.

In the sealing structure with a barrier membrane for an electronicelement section according to the present invention, the blocking regionmay be formed by a peripheral bank layer which is made of an organicmaterial, and whose surface is made liquid-repelling.

According to the above sealing structure with a barrier membrane for anelectronic element section, because the blocking region is formed by aperipheral bank layer whose surface is made liquid-repelling, theflattening resin layer cannot flow to the outside of the blockingregion, whereby reliability of the sealing structure can be improved.

In the sealing structure with a barrier membrane for an electronicelement section according to the present invention, the blocking regionmay be formed by a closed-loop liquid-repelling region extending on thesubstrate.

According to the above sealing structure with a barrier membrane for anelectronic element section, because the blocking region is a closed-loopliquid-repelling region formed on the substrate, the flattening resinlayer cannot flow to the outside of the blocking region, wherebyreliability of the sealing structure can be improved.

In the sealing structure with a barrier membrane for an electronicelement section according to the present invention, aliquid-affinity-treated membrane may be formed at least inside theblocking region on the substrate.

According to the above sealing structure with a barrier membrane for anelectronic element section, because a liquid-affinity-treated membraneis formed inside the blocking region on the substrate, adhesion betweenthe flattening resin layer deposited on the liquid-affinity-treatedmembrane and the substrate can be improved, and the barrier propertiescan also be improved.

In the sealing structure with a barrier membrane for an electronicelement section according to the present invention, the liquid-repellingregion may be formed by treating a portion of theliquid-affinity-treated membrane to make it liquid-repelling.

According to the above sealing structure with a barrier membrane for anelectronic element section, because the liquid-repelling region isformed by treating a portion of the liquid-affinity-treated membrane tomake it liquid-repelling, the position of the liquid-repelling regioncan be easily located at a predetermined position, whereby reliabilityof the sealing structure can be improved.

Next, a display device according to the present invention comprises: adisplay element formed or mounted on a substrate; a closed-loop blockingregion which is formed on the substrate so as to surround the entiredisplay element or a portion of the display element; and a multi-layeredsealing membrane which is formed by depositing at least one flatteningresin layer and at least one barrier layer on the display element,wherein the flattening resin layer is formed inside the blocking region.

According to the above display device, because the display element issealed by the multi-layered sealing membrane which is formed bydepositing at least one flattening resin layer and at least one barrierlayer, the multi-layered sealing membrane can be made thinner than a“sealing can” employed in a conventional sealing structure; therefore,the overall thickness of the display element can be reduced whencompared with the case of the conventional display element.

Moreover, because the flattening resin layer is formed, the barrierlayer formed on the flattening resin layer can be made flat, and asresult, a display element having sufficient barrier properties, i.e., inwhich cracking and pin holes in the barrier layer can be prevented, maybe provided.

In addition, because the flattening resin layer is formed inside theblocking region, the area where the flattening resin layer is formed canbe delimited by the blocking region; therefore, the size of theso-called frame region can be adjusted by the position of the blockingregion. As a result, the frame region may be made narrower than that ina conventional sealing structure so as to increase the size of thedisplay region. By delimiting the area where the flattening resin layeris formed, variation of the barrier properties depending on location canbe reduced, and reliability of sealing can be improved.

In addition, if the flattening resin layer, which is the closest to thesubstrate among flattening layers, is disposed so as to be adjacent tothe substrate where the electronic element section is not formed,contact area between the substrate and the multi-layered sealingmembrane can be increased, whereby the barrier properties of the displayelement against water and oxygen can be further improved.

In the display device according to the present invention, the barrierlayer may be formed so as to extend to the outside of the blockingregion.

According to the above display device, because the barrier layer isformed so as to extend to the outside of the blocking region, thebarrier layer having a wider area can be provided, whereby the barrierproperties can be further improved, and permeation of water, oxygen, orthe like into the display element can be more effectively prevented.

The display device according to the present invention may furthercomprise another blocking region or other blocking regions which aredisposed outside the main blocking region.

According to the above display device, because a plurality of blockingregions are formed including another blocking region or other blockingregions which are disposed outside the main blocking region, theflattening resin layer can be reliably blocked even when the flatteningresin layer is deposited thickly, whereby the barrier properties of themulti-layered sealing membrane can be further improved. As a result, itbecomes easy to form the multi-layered sealing membrane by alternatelydepositing the flattening resin layers and the barrier layers, and thusthe barrier properties against water, oxygen, or the like can be furtherimproved.

The display device according to the present invention may comprise aplurality of flattening resin layers, and each of the flattening resinlayers may be formed inside one of the blocking regions.

According to the above display device, because each of a plurality offlattening resin layers is formed inside one of the blocking regions,the flattening resin layers can be reliably blocked by the blockingregions even when a plurality of flattening resin layers are employed,whereby the barrier properties of the multi-layered sealing membrane canbe further improved.

The display device according to the present invention may comprise aplurality of barrier layers, and each of the barrier layers may beformed so as to extend to the outside of each of the blocking regions.

According to the above display device, because each of a plurality ofbarrier layers is formed so as to extend to the outside of each of theblocking regions, a wide area for each of the barrier layers can beensured, whereby the barrier properties of the multi-layered sealingmembrane can be further improved, and permeation of water, oxygen, orthe like into the display element can be more effectively prevented.

In the display device according to the present invention, the blockingregion may be formed by a peripheral bank layer which is made of anorganic material, and whose surface is made liquid-repelling.

According to the above display device, because the blocking region isformed by a peripheral bank layer whose surface is madeliquid-repelling, the flattening resin layer cannot flow to the outsideof the blocking region, whereby reliability of the sealing structure canbe improved.

In the display device according to the present invention, the blockingregion may be formed by a closed-loop liquid-repelling region extendingon the substrate.

According to the above display device, because the blocking region is aclosed-loop liquid-repelling region formed on the substrate, theflattening resin layer cannot flow to the outside of the blockingregion, whereby reliability of the sealing structure can be improved.

In the display device according to the present invention, aliquid-affinity-treated membrane may be formed at least inside theblocking region on the substrate.

According to the above display device, because a liquid-affinity-treatedmembrane is formed inside the blocking region on the substrate, adhesionbetween the flattening resin layer deposited on theliquid-affinity-treated membrane and the substrate can be improved, andthe barrier properties can also be improved.

In the display device according to the present invention, theliquid-repelling region may be formed by treating a portion of aliquid-affinity-treated membrane to make it liquid-repelling.

According to the above display device, because the liquid-repellingregion is formed by treating a portion of the liquid-affinity-treatedmembrane to make it liquid-repelling, the position of theliquid-repelling region can be easily located at a predeterminedposition, whereby reliability of the display element can be improved.

In the display device according to the present invention, the displayelement may preferably comprise a plurality of light emitting elements,and banks delimiting the light emitting elements, and each of the lightemitting elements may comprise an electrode, an active layer disposedadjacent to the electrode, and an opposing electrode disposed adjacentto the active layer.

The display device according to the present invention may furthercomprise a drive circuit for driving the display elements, and the drivecircuit may be encapsulated by at least one flattening resin layer andat least one barrier layer.

According to the above display device, because the drive circuit isencapsulated by at least one flattening resin layer and at least onebarrier layer, permeation of water, oxygen, or the like into the drivecircuit can be prevented, whereby reliability of the display element canbe further improved.

An electronic apparatus according to the present invention may compriseany one of the display devices according to the present invention.

According to the above electronic apparatus, because the electronicapparatus comprises any of the display devices described above, theoverall thickness of the electronic apparatus can be made thinner whileensuring reliability against permeation of water, oxygen, or the like.

Next, a method, according to the present invention, for fabricating adisplay device, which includes an electronic element section formed on asubstrate, may comprise the steps of: forming a closed-loop blockingregion on the substrate so as to surround the entire electronic elementsection or a portion of the electronic element section; coating a resincoating substance containing a resin monomer or a resin oligomer insidethe blocking region; polymerizing the resin coating substance aftercoating so as to form a flattening resin layer; and forming a barrierlayer so as to cover at least the flattening resin layer and theblocking region.

The electronic element section may be an EL (electroluminescent) displayelement, a semiconductor circuit element, or various circuits formed ona substrate or the like.

According to the above method for fabricating a display device, becausethe closed-loop blocking region is formed on the substrate, and a resincoating substance is coated on the inside of the blocking region, theflow of the resin coating substance is restrained by the blockingregion, whereby a sealing area can be freely defined, and thus a displaydevice can be fabricated in which the barrier properties aresubstantially uniform at any location on the substrate.

In addition, because the barrier layer is formed after the flatteningresin layer is made, cracking and pin holes in the barrier layer can beprevented, whereby the barrier properties against water and oxygen canbe improved.

In the method, according to the present invention, for fabricating adisplay device, the step of forming the flattening resin layer and thestep of forming the barrier layer may be alternately repeated aplurality of times so as to form a multi-layered sealing membrane inwhich the flattening resin layers and the barrier layers are overlaidalternately.

According to the above method for fabricating a display device, becausethe edges of the multi-layered sealing membrane can be formed in such amanner that the edges of the flattening resin layers and the barrierlayers, which are alternately deposited, are aligned with respect toeach other, the anti-permeation performance of the edges of themulti-layered sealing membrane against water and oxygen can be improved,and display devices having sufficient barrier properties can befabricated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view showing the wiring configuration of adisplay device according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view showing the display device according tothe first embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along the line A-A′ in FIG. 2.

FIG. 4 is a cross-sectional view taken along the line B-B′ in FIG. 2.

FIG. 5 is a process drawing illustrating a method for fabricating thedisplay device according to the first embodiment of the presentinvention.

FIG. 6 is another process drawing illustrating a method for fabricatingthe display device according to the first embodiment of the presentinvention.

FIG. 7 is another process drawing illustrating a method for fabricatingthe display device according to the first embodiment of the presentinvention.

FIG. 8 is another process drawing illustrating a method for fabricatingthe display device according to the first embodiment of the presentinvention.

FIG. 9 is another process drawing illustrating a method for fabricatingthe display device according to the first embodiment of the presentinvention.

FIG. 10 is another process drawing illustrating a method for fabricatingthe display device according to the first embodiment of the presentinvention.

FIG. 11 is another process drawing illustrating a method for fabricatingthe display device according to the first embodiment of the presentinvention.

FIG. 12 is another process drawing illustrating a method for fabricatingthe display device according to the first embodiment of the presentinvention.

FIG. 13 is a cross-sectional view showing the major portion of a sealingstructure in a display device according to a second embodiment of thepresent invention.

FIGS. 14A and 14B are process drawings respectively illustrating amethod for fabricating the display device according to the secondembodiment of the present invention.

FIGS. 15A, 15B, and 15C are process drawings respectively illustrating amethod for fabricating the display device according to the secondembodiment of the present invention.

FIG. 16 is a cross-sectional view showing the major portion of a sealingstructure in a display device according to a third embodiment of thepresent invention.

FIG. 17 is a schematic plan view showing a display device according to afourth embodiment of the present invention.

FIG. 18 is a cross-sectional view taken along the line A-A′ in FIG. 17.

FIG. 19 is a cross-sectional view taken along the line B-B′ in FIG. 17.

FIG. 13 is another process drawing illustrating a method for fabricatingthe display device according to the first embodiment of the presentinvention.

FIGS. 20A, 20B, and 20C are perspective views respectively showingelectronic apparatuses according to a fifth embodiment of the presentinvention.

FIG. 21 is a plan view showing a positional relationship between a mask,which is used when resin coating substance is applied, and a mothersubstrate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

An example as a first embodiment of the present invention, in whichdisplay elements for an organic EL display device (a display device) areapplied to an electronic element section, will be explained below withreference to the drawings. This embodiment is merely an example of thepresent invention, and the present invention is not limited to thisembodiment to which various modifications may be made within the scopeof the present invention. In the drawings to which, hereinafter,reference is made, scale factors for various layers and various elementsmay be differently set in order to facilitate understanding of thevarious layers and various elements in the drawings.

FIG. 1 is a schematic plan view showing the wiring configuration of adisplay device (an organic EL display device) according to the firstembodiment of the present invention. The display device 1 shown in FIG.1 is an organic EL display device of an active matrix type in which thinfilm transistors (TFTs) are employed as direct drive elements.

The display device 1 shown in FIG. 1 comprises scanning lines 101,signal lines 102 which extend perpendicularly to the scanning lines 101,source lines for luminance 103 which extend in parallel to the signallines 102, and pixels A, each provided in the vicinity of each of theintersecting points of the scanning lines 101 and the signal lines 102.

A data side drive circuit 104, which comprises a shift register, a levelshifter, and video lines, is connected to each of the signal lines 102.Scanning line drive circuits 105, which comprise a shift register and alevel shifter, are connected to each of the scanning lines 101.

Moreover, to each of the pixels A, a switching TFT 142 whose gateelectrode is provided with scanning signals via the scanning lines 101,a retaining capacitor Cap for retaining image signals provided from thesignal lines 102 via the switching TFT 142, a current TFT 123 whose gateelectrode is provided with the image signals retained by the retainingcapacitor Cap, a pixel electrode (a first electrode) 111 to which drivecurrent is supplied from the source lines for luminance 103 when thepixel electrode 111 is electrically connected to the source lines forluminance 103, an active layer 110 sandwiched between the pixelelectrode 111 and a cathode electrode 12 (a second electrode), areprovided. The cathode electrode 12 is connected to a source circuit forcathode 131.

Furthermore, the active layer 110 includes a luminescent layercomprising a hole-injection/transportation layer and an organicelectroluminescent layer formed so as to be adjacent to thehole-injection/transportation layer. The luminescent layer comprisesthree kinds of luminescent layers, i.e., a luminescent layer 110Remitting red light, a luminescent layer 110G emitting green light, and aluminescent layer 110B emitting blue light, which are arranged in astripe pattern.

In addition, the source lines for luminance 103R, 103G, and 103B, whichare connected to the luminescent layers 110R, 110G, and 110B via thecurrent TFT 123, respectively, are connected to source circuits forluminance 132. The source lines for luminance 103R, 103G, and 103B arerespectively provided for colors because the drive voltages should bedifferently set depending on colors, i.e., depending on the luminescentlayers 110R, 110G, and 110B.

In the display device 1, when the switching TFT 142 is turned on by thedrive of the scanning lines 101, electrical potential in the signallines 102 at the time is retained in the retaining capacitor Cap, andthe current TFT 123 is turned on or off depending on the state of theretaining capacitor Cap. Drive currents flow from the source lines forluminance 103R, 103G, and 103B to the pixel electrode 111 via thechannels of the current TFT 123, and electrical currents flow to thecathode electrode (second electrode) via the luminescent layers 110R,110G, and 110B. Each of the active layers 110 emits light depending onthe magnitude of electrical current flowing therethrough.

Next, the specific configurations of the display device 1 according tothe present embodiment will be explained with reference to FIGS. 2 to 4.FIG. 2 is a schematic plan view showing the display device according tothe present embodiment, FIG. 3 is a cross-sectional view taken along theline A-A′ in FIG. 2, and FIG. 4 is a cross-sectional view taken alongthe line B-B′ in FIG. 2.

As shown in FIGS. 2, 3, and 4, in the display device 1 according to thepresent embodiment, a display section 11 a, in which the pixelelectrodes (electrodes) connected to the current TFT (not shown) arearranged in a matrix pattern, and a non-display section 11 b disposedaround the display section 11 a, are provided on a transparent substrate2 made of glass, plastic, or the like. The non-display section 11 bcomprises the source lines for luminance 103 (103R, 103G, and 103B)respectively connected to the pixel electrodes, and the scanning linedrive circuits 105. In the display section 11 a, there is provided adisplay element section (an electronic element section) 3 having asubstantially rectangular shape in a plan view.

As shown in FIG. 2, the source lines for luminance 103R, 103G, and 103Bprovided in the non-display section 11 b extend from the bottom of thesubstrate 2, as viewed in FIG. 2, toward the top along the scanning linedrive circuits 105, turn to the left at the end of the scanning linedrive circuits 105, extend along the edge of the display element section3, and then are connected to the pixel electrodes (not shown) providedin the display element section 3.

In addition, as shown in FIGS. 2 and 4, a flexible tape 130, whose baseis made of polyimide or polyester, and on which control IC 130 a ispackaged, is adhered to an end of the substrate 2. The control IC 130 acomprises therein the data side drive circuit 104, the source circuitfor cathode 131, and the source circuits for luminance 132 shown inFIG. 1. There are provided a plurality of external terminals 130 b onthe flexible tape 130, which extend from the control IC 130 a, and whichare arranged along a side of the flexible tape 130.

Next, as shown in FIGS. 3 and 4, there is formed a circuit section 11 onthe substrate 2, and the display element section 3 is formed on thecircuit section 11. The display section 11 a is disposed in the middleof the circuit section 11. In a portion of the circuit section 11 thatis contained in the display section 11 a, there are provided the currentTFTs 123, and the pixel electrodes 111 connected to the current TFTs123. The current TFTs 123 are embedded between a substrate protectivelayer 281 and a second interlayer insulation layer 283 and firstinterlayer insulation layer 284. The pixel electrodes are formed on thefirst interlayer insulation layer 284. In the circuit section 11, thereare also provided the retaining capacitor Cap and the switching TFT 142;however, these are not shown in FIGS. 3 and 4.

There are provided banks 112 between the pixel electrodes 111. The bank112 comprises an inorganic bank layer 112 a formed on the firstinterlayer insulation layer 284, and an organic bank layer 112 b formedon the inorganic bank layer 112 a. The inorganic bank layer 112 a isformed so as to cover not only the display section 11 a, but also thenon-display section, substantially. The surface of the inorganic banklayer 112 a is made to have liquid-affinity, while on the other hand,the surface of the organic bank layer 112 b is made liquid-repelling.Moreover, the active layer 110 is formed on each of the pixel electrodes111, and the cathode electrode 12 is formed on the active layers 110 andorganic bank layers 112 b. The inorganic bank layer 112 a and organicbank layer 112 b are formed so as to partially overlap with the pixelelectrode 111, and more specifically, the inorganic bank layer 112 aextends closer to the middle of the pixel electrode 111 than the organicbank layer 112 b. Note that a shading layer may be provided between theinorganic bank layer 112 a and the organic bank layer 112 b.

The organic bank layer 112 b is made of an ordinary resist such asacrylic resin, polyimide resin, or the like. The thickness of theorganic bank layer 112 b is preferably set to be 0.1 to 3.5 μm, and morepreferably, is set to be approximately 2 μm. If the thickness thereof isless than 0.1 μm, the thickness of the organic bank layer 112 b may beless than the total thickness of the hole-injection/transportation layerand of the luminescent layer, and as a result, the luminescent layer, ina liquid state, may overflow beyond an upper opening 112 d, which is notpreferable. On the other hand, if the thickness thereof is greater than3.5 μm, the step due to the upper opening 112 d may be too large, and asa result, a step coverage of the cathode electrode 12 formed on theorganic bank layer 112 b may not be sufficiently ensured, which is alsonot preferable. The thickness of the organic bank layer 112 b may be setto be greater than 2 μm, which is more preferable because electricalinsulation performance between the cathode electrode 12 and the pixelelectrode 111 can be enhanced.

There are provided sections made to have liquid-affinity and sectionsmade liquid-repelling on and around the banks 112. The sections made tohave liquid-affinity include the inorganic bank layers 112 a and thepixel electrodes 111, into which liquid-affinitive group such ashydroxyl group are infiltrated by a plasma treatment using oxygen as areaction gas. The sections made liquid-repelling include the organicbank layers 112 b, into which liquid-repelling group such as fluorineare infiltrated by a plasma treatment using tetrafluoromethane as areaction gas.

As shown in FIGS. 3 and 4, the active layers 110 are deposited on thepixel electrodes 111, respectively. The banks 112 are respectivelyprovided between the pixel electrodes 111, and between the active layers110 so as to divide the active layers 110. Each of the active layers 110comprises the hole-injection/transportation layer (not shown) depositedon the pixel electrode 111, and the luminescent layer (not shown) formedadjacent to the hole-injection/transportation layer. In the luminescentlayer, holes injected from the hole-injection/transportation layer andelectrons emitted from the cathode electrode are combined to emitluminous light. The luminescent layer includes three kinds ofluminescent layers, i.e., a red luminescent layer 110R emitting redlight, a green luminescent layer 110G emitting green light, and a blueluminescent layer 110B emitting blue light, which are arranged, forexample, in a stripe pattern. Note that the luminescent layers are notnecessarily arranged in a stripe pattern, but may be arranged in amosaic pattern, or in a deltaic pattern.

The cathode 12 comprises a first cathode layer 12 b made of lithiumfluoride and calcium layered product, and a second cathode layer 12 cmade of Al (aluminum), Ag (silver), or Mg/Ag (magnesium/silver) layeredproduct. The first cathode layer 12 b is provided merely on the organicbank layers 112 b, while on the other hand, the second cathode layer 12c is formed on the organic bank layers 112 b, as well as on thenon-display section 11 b, and is connected to a cathode line 12 a. Thecathode electrode 12, as the opposing electrode of the pixel electrode111, functions to supply electricity to the active layer 110.

Next, as shown in FIGS. 2 and 3, there are provided scanning drivecircuits 105 in the non-display section disposed in either sides of thedisplay element section 3. The scanning drive circuit 105 comprises anN-channel type or a P-channel type TFT 105 c forming an inverterincluded in the shift register. The TFT 105 c has substantially the samestructure as that of the current TFT 123 except for not being connectedto the pixel electrode 111.

As shown in FIG. 3, there are formed signal lines 105 a for a scanningcircuit on portions of the substrate protective layer 281 that arelocated in the vicinity of the scanning drive circuits 105. In addition,there are provided source lines 105 b for a scanning circuit on portionsof the second interlayer insulation layer 283 that are located in thevicinity of the signal lines 105 a for a scanning circuit.

Moreover, as shown in FIG. 3, there are provided the source lines forluminance 103R, 103G, and 103B in the vicinity of the source lines 105 bfor a scanning circuit.

Furthermore, as shown in FIG. 3, the cathode line 12 a, which isconnected to the cathode electrode 12, is formed in portion of thenon-display section 11 b that are located outwardly relative to thesource lines for luminance 103R, 103G, and 103B. The cathode line 12 ais formed substantially in a U-shape in plan view so as to surround thesource lines for luminance 103R, 103G, and 103B.

Next, a sealing structure for the display device 1 of the presentembodiment will be explained.

As shown in FIGS. 2, 3, and 4, there is formed a closed-loop peripheralbank layer 14 a (a blocking region) on the substrate 2 and around thedisplay element section 3. As shown in FIGS. 3 and 4, a multi-layeredsealing membrane 14 b is deposited on the display element section 3. Themulti-layered sealing membrane 14 b is formed by alternately depositingtwo flattening resin layers 14 c (i.e., 14 c 1 and 14 c 2) and twobarrier layers 14 d (i.e., 14 d 1 and 14 d 2). The flattening resinlayers 14 c 1 and 14 c 2 are formed inside the closed-loop peripheralbank layer 14 a while being blocked by the peripheral bank layer 14 a.The barrier layers 14 d 1 and 14 d 2 are formed on the flattening resinlayers 14 c 1 and 14 c 2 (in an area inside the peripheral bank layer 14a), and the edge portions 14 e (i.e., 14 e 1 and 14 e 2) thereof extendover the peripheral bank layer 14 a. The number of layers of theflattening resin layers 14 c and of the barrier layers 14 d may befreely selected to be one or more; however, two to four is preferred.

The thickness of the peripheral bank layer 14 a is set to be 1 to 3 μm,and the surface of the peripheral bank layer 14 a is madeliquid-repelling as in the case of the organic bank layer 112 b.

The flattening resin layers 14 c are made of, for example, polyacrylicresin or the like. The flattening resin layers 14 c are formed toflatten the surface of the display device 1 by filling the step (e.g., 1to 3 μm) between the non-display section 11 b and the display section 11a (i.e., between the inorganic bank layer 112 a formed in thenon-display section 11 b and the display element section 3), andfunctions to make the step coverage of the barrier layers 14 d formed onthe flattening resin layers 14 c as small as possible so that crackingand pin holes in the barrier layers 14 d and uneven thickness of thebarrier layers 14 d can be prevented. The barrier layers 14 d are madeof an inorganic membrane such as SiO₂, and are superior in blockingwater and oxygen. The multi-layered sealing membrane 14 b is formed byoverlaying the flattening resin layers 14 c and the barrier layers 14 d,and functions to prevent degradation of the cathode electrode 12 and theactive layer 110 by inhibiting permeation of water, oxygen, impurityions, or the like into the display element section 3.

The sealing structure will be more specifically explained. As shown inFIGS. 3 and 4, the lowermost flattening resin layer 14 c 1 among theflattening resin layer 14 c is formed on the inorganic bank layer 112 a(liquid-affinitive membrane) in the non-display section 11 b and on thedisplay element section 3 while being blocked by the inner side of theperipheral bank layer 14 a. The flattening resin layer 14 c 1 is formedto be thinner than the peripheral bank layer 14 a. Because the surfaceof the inorganic bank layer 112 a is made to have liquid-affinity, theflattening resin layer 14 c 1 made of polyacrylic resin or the like iseasily settled on the inorganic bank layer 112 a, and thus adhesionbetween the inorganic bank layer 112 a and the flattening resin layer 14c 1 is sufficiently ensured. On the other hand, because the surface ofthe peripheral bank layer 14 a is made liquid-repelling, the peripheralbank layer 14 a does not accept the flattening resin layer 14 c 1, andas a result, the flattening resin layer 14 c 1 is reliably blocked bythe peripheral bank layer 14 a.

Next, the barrier layer 14 d 1 is formed on the flattening resin layer14 c 1. The barrier layer 14 d 1 is formed so as to cover the peripheralbank layer 14 a, and extends over the peripheral bank layer 14 a to theoutside of the peripheral bank layer 14 a so that the edge portion 14 e1 of the barrier layer 14 d 1 is located on the first interlayerinsulation layer 284. In the vicinity of the peripheral bank layer 14 a,a step 14 f is formed due to the thickness difference between theflattening resin layer 14 c 1 and the peripheral bank layer 14 a. Thebarrier layer 14 d 1 extends over the step 14 f to the outside of theperipheral bank layer 14 a.

Moreover, another flattening resin layer 14 c 2 is formed on the barrierlayer 14 d 1. The flattening resin layer 14 c 2 is blocked by the step14 f between the peripheral bank layer 14 a and the flattening resinlayer 14 c 1 while being disposed inside the peripheral bank layer 14 a.As shown in FIGS. 3 and 4, the level of the upper surface of theflattening resin layer 14 c 2 is set to substantially coincide with thelevel of the upper surface of the peripheral bank layer 14 a in thisembodiment; however, the level of the upper surface of the flatteningresin layer 14 c 2 may be set to be lower than the level of the uppersurface of the peripheral bank layer 14 a.

Furthermore, another barrier layer 14 d 2 is formed on the flatteningresin layer 14 c 2. The barrier layer 14 d 2 is formed so as to coverthe peripheral bank layer 14 a as in the case of the barrier layer 14 d1, and extends over the peripheral bank layer 14 a to the outside of theperipheral bank layer 14 a so that the edge portion 14 e 2 of thebarrier layer 14 d 2 is located on the first interlayer insulation layer284. Because the flattening resin layer 14 c 2 under the barrier layer14 d 2 is blocked by the inner surface of the peripheral bank layer 14a, the barrier layers 14 d 1 and 14 d 2 directly contact each other atthe outside of the peripheral bank layer 14 a.

As mentioned above, the peripheral bank layer 14 a is made of a resisthaving thermal resistance and solvent resistance, such as acrylic resin,polyimide resin, or the like, and is made liquid-repelling. Thethickness of the peripheral bank layer 14 a is preferably set to be 0.1to 3.5 μm, and more preferably, is set to be approximately 2 μm. If thethickness thereof is less than 0.1 μm, the flattening resin layer 14 ccannot be blocked, which is not preferable. On the other hand, if thethickness thereof is greater than 3.5 μm, fabrication may becomeunstable due to a large ratio of sectional form, which is also notpreferable.

Both of the flattening resin layers 14 c 1 and 14 c 2 are made ofacrylic resin. The thicknesses of the flattening resin layers 14 c 1 and14 c 2 are preferably set to be 0.05 to 3 μm, and more preferably, areset to be approximately 0.1 to 1 μm. If the thicknesses thereof are lessthan 0.05 μm, the flatness thereof may be degraded, which is notpreferable. On the other hand, if the thicknesses thereof are greaterthan 3 μm, the flattening resin layer 14 c may be deposited over theperipheral bank layer 14 a, which is also not preferable. Thethicknesses of the flattening resin layers 14 c 1 and 14 c 2 may be setto be either the same or different with respect to each other.

Furthermore, the barrier layers 14 d 1 and 14 d 2 are made of SiO₂,Al₂O₃, or the like. The thicknesses of the barrier layers 14 d 1 and 14d 2 are preferably set to be 5 to 500 nm, and more preferably, are setto be approximately 30 to 300 nm. If the thicknesses thereof are lessthan 5 nm, permeation of water and oxygen may not be prevented, which isnot preferable. On the other hand, if the thicknesses thereof aregreater than 500 nm, the barrier layers 14 d 1 and 14 d 2 may easilyhave cracking due to thermal stress or mechanical stress, which is alsonot preferable. The thicknesses of the barrier layers 14 d 1 and 14 d 2may be set to be either the same or different with respect to eachother.

By employing the above configurations, the thickness of themulti-layered sealing structure 14 b may be set to be 1 to 3 μm. Inaddition, the thickness of the sealing structure in the display deviceand above the first interlayer insulation layer 284 may be set to be 1to 3 μm.

By employing the above sealing structure, the multi-layered sealingstructure 14 b may be formed to be thin, and thus the overall thicknessof the display device 1 can be made much less than that of a displaydevice in which a conventional “sealing can” is employed. Because theflattening resin layers 14 c are provided, the barrier layers 14 dformed on the flattening resin layers 14 c can be made flat, and as aresult, cracking and pin holes in the barrier layers 14 d can beprevented, whereby a sealing membrane having excellent barrierproperties can be provided.

In addition, because the flattening resin layers 14 c are formed insidethe peripheral bank layer 14 a, the area where the flattening resinlayers 14 c are formed can be delimited by the peripheral bank layer 14a; therefore, the size of the so-called frame region can be adjusted bythe position of the peripheral bank layer 14 a. As a result, the frameregion may be made narrower than that in a conventional sealingstructure so as to increase the size of the display section 11 a. Bydelimiting the area where the flattening resin layer 14 c is formed,variation of the barrier properties depending on location can bereduced, and reliability of sealing can be improved.

Moreover, if the flattening resin layer 14 c 1, which is the closest tothe substrate 2 among flattening layers, is disposed so as to beadjacent to the substrate 2 in the non-display section 11 b where thedisplay element section 3 is not formed, contact area between thesubstrate 2 and the multi-layered sealing membrane 14 b can beincreased, whereby the barrier properties of the electronic elementsection at the membrane boundaries against water and oxygen can befurther improved.

Next, a method for fabricating the electronic element section accordingto the present embodiment will be explained using the appended drawingswhile referring to the display device shown in FIGS. 1 to 4 as anexample. The method for fabricating a display device comprises the stepsof forming a closed-loop blocking region on the substrate 2, coating aresin coating substance containing a resin monomer or a resin oligomerinside the blocking region, polymerizing the resin coating substanceafter coating so as to form a flattening resin layer, and forming abarrier layer so as to cover at least the flattening resin layer and theblocking region. In the above method, the step of forming the flatteningresin layer and the step of forming the barrier layer is alternatelyrepeated a plurality of times so as to form a multi-layered sealingmembrane in which the flattening resin layers and the barrier layers areoverlaid alternately.

The methods for fabricating the display element section 3 (electronicelement section) on the circuit 11 on the substrate 2, and forfabricating the sealing structure for sealing the display elementsection 3 will be explained below with reference to FIGS. 5 to 12. Thecross sections shown in FIGS. 5 to 12 are taken along the line A-A′ inFIG. 2. As shown in FIG. 5, the circuit 11 is formed on the substrate 2,and then a membrane made of transparent electrode material such as ITO(Indium Tin Oxide) is formed so as to cover the circuit 11, and afterthat, the pixel electrodes 111 are formed on the first interlayerinsulation layer 284 by applying a patterning process to the membrane.The pixel electrodes 111 are formed only in an area where the currentTFTs 123 are formed, and are connected to the current TFTs 123 viacontact holes 111 a.

Next, as shown in FIG. 6, the inorganic bank layers 112 a are formed onthe first interlayer insulation layer 284 and pixel electrodes 111. Theinorganic bank layers 112 a are formed so as to expose portions of thepixel electrode 111, respectively. The inorganic bank layers 112 a areformed not only in the display section 11 a, but also in the non-displaysection on the substrate 2. The inorganic bank layers 112 a are formedby executing the steps of forming an inorganic membrane made of such asSiO₂, TiO₂, SiN on the entire surfaces of the first interlayerinsulation layer 284 and pixel electrodes 111 using, for example, a CVDprocess, a TEOS process, a sputtering process, a vapor depositionprocess, or the like, and applying a patterning process to the inorganicmembrane.

Moreover, as shown in FIG. 6, the organic bank layers 112 b are formedon the inorganic bank layers 112 a. The organic bank layers 112 b areformed so as to expose portions of the pixel electrode 111 through theinorganic bank layers 112 a, respectively. In this manner, the banks 112are formed on the first interlayer insulation layer 284.

Furthermore, in the step of forming the blocking region, the peripheralbank layer 14 a is formed on the inorganic bank layers 112 a in thenon-display section 11 b simultaneously with the forming process of theorganic bank layers 112 b.

Next, regions exhibiting liquid-affinity and regions exhibitingliquid-repellency are formed on the surface of the banks 112. In thisembodiment, both regions are made using plasma treatment processes. Inparticular, the plasma treatment processes include a liquid-affinitiveprocess in which the pixel electrode 111 and the inorganic bank layers112 a are made to have liquid-affinity, and a liquid-repelling processin which the organic bank layers 112 b and the peripheral bank layer 14a are made liquid-repelling.

More specifically, the banks 112 are heated to a predeterminedtemperature (e.g., 70 to 80° C.), and then a plasma treatment (O₂ plasmatreatment) as the liquid-affinitive process, in which oxygen is used asa reaction gas, is applied to the banks 112 under atmosphericconditions. Next, another plasma treatment (CF₄ plasma treatment) as theliquid-repelling process, in which tetrafluoromethane is used as areaction gas, is applied to the banks 112 under atmospheric conditions,and then the banks 112, which have been heated for the plasmatreatments, are cooled to room temperature to obtain the regionsexhibiting liquid-preference and the regions exhibitingliquid-repellency. In FIG. 7, the contours of the pixel electrode 111and the inorganic bank layers 112 a, which are made to haveliquid-affinity, are shown by solid lines, and the contours of theorganic bank layers 112 b and the peripheral bank layer 14 a, which aremade liquid-repelling, are shown by alternate long and short dash lines.

Next, as shown in FIG. 8, the active layers 110 are formed on the pixelelectrodes 111 using an ink-jet method. The active layers 110 are formedthrough the steps of ejecting and drying a composite ink containingmaterial for the hole-injection/transportation layer, and ejecting anddrying another composite ink containing material for the luminescentlayer.

Next, as shown in FIG. 9, the cathode electrode 12, which covers thebanks 112 and the active layers 110, is formed. The cathode electrode 12can be obtained through the steps of forming the first cathode layer 12b on the banks 112 and the active layers 110, and forming the secondcathode layer 12 c which covers the first cathode layer 12 b, and whichis to be connected to the cathode line 12 a disposed on the substrate 2.

Next, as shown in FIG. 10, as the steps for fabricating the flatteningresin layer, a resin coating substance containing a resin monomer or aresin oligomer, or an organic silicide (e.g., TEOS(tetraethylorthosilicate), Si₃N₄) is heated and vaporized under vacuumconditions, the vaporized substance is sprayed on the inorganic banklayer 112 b, which is disposed on the display element section 3 and inthe non-display section, and inside the peripheral bank layer 14 a, andultraviolet light is emitted on the sprayed substance under vacuumconditions using an ultraviolet lamp, such as a mercury lamp, a metalhalide lamp, or the like, so as to polymerize the resin monomer or theresin oligomer contained in the resin coating substance, and so as toform the flattening resin layer 14 c 1. When the resin coating substanceis sprayed, a mask M1 having an opening m1 is disposed above thesubstrate 2 while being positioned so that the opening m1 is alignedwith the inside portion of the peripheral bank layer 14 a formed on thesubstrate 2, and the resin coating substance is preferably sprayedthrough the opening m1. By using the mask M1, the resin coatingsubstance is prevented from being deposited outside the peripheral banklayer 14 a. Plasma radiation may be used to polymerize the resin monomeror the resin oligomer.

The resin coating substance exhibits a viscosity less than 500 cP, andpreferably less than 100 cP, at room temperature, which means that theresin coating substance has substantial flowability; however, becausethe resin coating substance after being sprayed is blocked by theperipheral bank layer 14 a, the resin coating substance cannot flow tothe outside of the peripheral bank layer 14 a. In this manner, theflattening resin layer 14 c 1 is formed inside the peripheral bank layer14 a. Note that the thickness of the flattening resin layer 14 c 1 canbe adjusted by the amount of the sprayed resin, and the thicknessthereof is preferably set to be 0.1 to 1 μm.

The resin coating substance in this embodiment comprises: a primaryconstituent, i.e., a resin constituent, which may be selected from vinylresin monomers such as acrylic resin monomer, methacrylic resin monomer,polyester resin monomer, PET resin monomer, polypropylene resin monomer,or the like, or from vinyl resin oligomers such as acrylic resinoligomer, methacrylic resin oligomer, polyester resin oligomer, PETresin oligomer, polypropylene resin oligomer, or the like; and asecondary constituent consisting of a photopolymerization intiator. Morespecifically, the primary constituent may be selected from acrylic resinmonomers or acrylic resin oligomers having a polymerizable double bond,such as alkyd resin, polyester acrylate, polyether acrylate, acrylicacrylate, urethane acrylate, epoxy acrylate, silicone acrylate,polyacetal acrylate, polybutadiene acrylates, melamine acrylate, or thelike. Moreover, the resin monomer or resin oligomer may be selected fromvarious compounds such as monofunctional compounds, bifunctionalcompounds, trifunctional compounds, and multifunctional compounds,depending on the number of acryloyl group being contained. Two or moreacrylic resin monomers or acrylic resin oligomers may be mixed for use.In addition, the molecular weight of the acrylic resin monomer oracrylic resin oligomer to be used is preferably less than 10,000, ismore preferably less than 2,000, and is more preferably from 100 to 600.

The photopolymerization intiator as the secondary constituent may beselected from benzoin ethers, benzophenones, xanthones, and acetophenonederivatives. The amount of the photopolymerization intiator maypreferably be 0.01 to 10 pats by weight, and more preferably 0.1 to 2pats by weight when the amount of the acrylic resin monomer or acrylicresin oligomer as the primary constituent is 100 pats by weight.

The resin coating substance in this embodiment may be prepared by mixingthe primary constituent consisting of acrylic resin monomer or acrylicresin oligomer and the secondary constituent consisting of aphotopolymerization intiator. The viscosity of the resin coatingsubstance is preferably set to be less than 500 cP, and more preferablyset to be less than 100 cP at room temperature, so that irregularity inthe display section may be reliably flattened.

Next, as shown in FIG. 11, as the step for fabricating the barrierlayer, the barrier layer 14 d 1 is formed on the flattening resin layer14 c 1 using a vapor deposition process. The barrier layer 14 d 1 may beformed using metal such as aluminum, silicon, magnesium, titanium,indium, tin, or metal oxide (SiO₂, Al₂O₃) or the like, as a vapordeposition material. The vapor deposition process may be selected from avacuum vapor deposition process, a sputtering process, an ion platingprocess, or the like.

When the vapor deposition process is performed, another mask M2 havingan opening m2 is preferably disposed above the substrate 2 while beingpositioned so that the peripheral portion of the opening m2 is alignedwith the outside peripheral portion of the peripheral bank layer 14 aformed on the substrate 2, and vaporized substance is preferably appliedand deposited through the opening m2. By using the mask M2, the barrierlayer 14 d 1 is prevented from being formed on the side edges of thesubstrate 2. The thickness of the barrier layer 14 d 1 is preferably setto be 5 to 500 nm.

Because the barrier layer 14 d 1 can be made substantially flat due tothe flattening resin layer 14 c 1, the barrier layer 14 d 1, which isdense without having defects such as pin holes or cracking, can beobtained.

Moreover, because the barrier layer 14 d 1 is formed on the flatteningresin layer 14 c 1, adhesion between the flattening resin layer 14 c 1and the barrier layer 14 d 1 is improved due to an anchor effect of theflattening resin layer 14 c 1, and the barrier properties against waterand oxygen can be improved.

Next, as shown in FIG. 12, by repeating the above-mentioned flatteningresin layer forming step and the barrier layer forming step, theflattening resin layer 14 c 2 and the barrier layer 14 d 2 aresequentially formed on the barrier layer 14 d 1, and thus themulti-layered sealing membrane 14 b is obtained.

Through the steps described above, the display device 1 shown in FIGS. 1to 4 can be obtained.

Second Embodiment

Next, a second embodiment will be explained below with reference to FIG.13. FIG. 13 is a cross-sectional view showing the major portion of thesealing structure of a display device 201.

The elements of the display device 201 shown in FIG. 13 that are commonto those of the display device 1 of the first embodiment shown in FIGS.1 to 4 will be provided with the same reference symbols, and explanationtherefor will be simplified or omitted.

As shown in FIG. 13, the display device 201 of the present embodiment isprovided with a plurality of peripheral banks (blocking regions) 214 a1, 213 a 2, and 214 a 3. The innermost peripheral bank is indicated byreference symbol 214 a 1, another peripheral bank indicated by referencesymbol 214 a 2 is formed outside the peripheral bank layer 214 a 1, anda further peripheral bank layer 214 a 3 is formed outside the peripheralbank layer 214 a 2.

The distances “d” between the peripheral bank layer 214 a 1 and theperipheral bank layer 214 a 2, and between the peripheral bank layer 214a 2 and the peripheral bank layer 214 a 3 are preferably set to be 10 to300 μm. The material and thickness of each of the peripheral bank layers214 a 1, 214 a 2, and 214 a 3 are substantially the same as those of theperipheral bank layer 14 a in the first embodiment. The thicknesses ofthe peripheral bank layers 214 a 1, 214 a 2, and 214 a 3 may be eitherthe same or different with respect to each other.

There is formed a multi-layered sealing membrane indicated by referencesymbol 214 b on the display device 201. The multi-layered sealingmembrane 214 b comprises three flattening resin layers 214 c 1, 214 c 2,and 214 c 3, and three barrier layers 214 d 1, 214 d 2, and 214 d 3,which are formed by depositing alternately.

The lowermost flattening resin layer 214 c 1, among three flatteningresin layers 214 c 1, 214 c 2, and 214 c 3, is formed on the inorganicbank layer 112 a (liquid-affinitive membrane) in the non-display section11 b and on the display element section (not shown), and is blocked bythe inner surface (the left surface in FIG. 13) of the innermostperipheral bank layer 214 a 1. The thickness of the lowermost flatteningresin layer 214 c 1 is made to be less than that of the innermostperipheral bank layer 214 a 1. Because the surface of the inorganic banklayer 112 a is made to have liquid-affinity (i.e., covered by oxide),the flattening resin layer 214 c 1 made of polyacrylic resin or the likeis easily settled on the inorganic bank layer 112 a, and thus adhesionbetween the inorganic bank layer 112 a and the flattening resin layer214 c 1 is sufficiently ensured. On the other hand, because the surfaceof the peripheral bank layer 214 a 1 is made liquid-repelling, theperipheral bank layer 214 a 1 does not accept the flattening resin layer214 c 1, and as a result, the flattening resin layer 214 c 1 is reliablyblocked by the peripheral bank layer 214 a 1. Note that aliquid-repelling treatment does not have to be applied in order toachieve the objects of the present invention.

Next, the barrier layer 214 d 1 is formed on the flattening resin layer214 c 1. The barrier layer 214 d 1 is formed so as to cover threeperipheral bank layers 214 a 1, 214 a 2, and 214 a 3, and extends overthe entirety of the peripheral bank layers 214 a 1, 214 a 2, and 214 a 3to the outside of the outermost peripheral bank layer 214 a 3 so thatthe edge portion 214 e 1 of the barrier layer 214 d 1 is located on theinorganic bank layer 112 a. In the vicinity of the innermost peripheralbank layer 214 a 1, a step 214 f 1 is formed due to the thicknessdifference between the flattening resin layer 214 c 1 and the peripheralbank layer 214 a 1. The barrier layer 214 d 1 extends over the step 214f 1 to the outside of the outermost peripheral bank layer 214 a 3.

Moreover, another flattening resin layer 214 c 2 is formed on thebarrier layer 214 d 1. The flattening resin layer 214 c 2 is formed onthe barrier layer 214 d 1, extends over the innermost peripheral banklayer 214 a 1, and is blocked by the inner surface of the adjacentperipheral bank layer 214 a 2. Because the barrier layer 214 d 1 formedin advance is made of SiO₂ or the like, i.e., the surface thereof ismade to have liquid-affinity, the flattening resin layer 214 c 2 made ofpolyacrylic resin or the like is easily settled on the barrier layer 214d 1, and as a result, the flattening resin layer 214 c 2 extends overthe step 214 f 1 to reach the inner surface of the adjacent peripheralbank layer 214 a 2.

Next, another barrier layer 214 d 2 is formed on the flattening resinlayer 214 c 2. The barrier layer 214 d 2 is formed so as to cover twoperipheral banks 214 a 2 and 214 a 3, and extends to the outside of theoutermost peripheral bank layer 214 a 3 so that the edge portion 214 e 2of the barrier layer 214 d 2 is located on the inorganic bank layer 112a. In the vicinity of the peripheral bank layer 214 a 2, a step 214 f 2is formed due to the thickness difference between the flattening resinlayer 214 c 2 and the peripheral bank layer 214 a 2. The barrier layer214 d 2 extends over the step 214 f 2 to the outside of the outermostperipheral bank layer 214 a 3.

Moreover, a further flattening resin layer 214 c 3 is formed on thebarrier layer 214 d 2. The flattening resin layer 214 c 3 is formed onthe barrier layer 214 d 2, extends over two peripheral bank layers 214 a1 and 214 a 2, and is blocked by the inner surface of the outermostperipheral bank layer 214 a 3. Because the barrier layer 214 d 2 formedin advance is made of an oxide such as SiO₂ or the like, i.e., thesurface thereof is made to have liquid-affinity, the flattening resinlayer 214 c 3 made of polyacrylic resin or the like is easily settled onthe barrier layer 214 d 2, and as a result, the flattening resin layer214 c 3 extends over the steps of two peripheral bank layers 214 a 1 and214 a 2 to reach the inner surface of the adjacent peripheral bank layer214 a 3.

Next, a further barrier layer 214 d 3 is formed on the flattening resinlayer 214 c 3. The barrier layer 214 d 3 is formed so as to cover theoutermost peripheral bank layer 214 a 3, and extends to the outside ofthe outermost peripheral bank layer 214 a 3 so that the edge portion 214e 3 of the barrier layer 214 d 3 is located on the inorganic bank layer112 a.

In this manner, in the display device 201 of the present embodiment, aplurality of peripheral bank layers 214 a 1, 214 a 2, and 214 a 3 areformed, the flattening resin layers 214 c 1, 214 c 2, and 214 c 3 areformed inside the peripheral bank layers 214 a 1, 214 a 2, and 214 a 3,respectively, and the barrier layers 214 d 1, 214 d 2, and 214 d 3extend to the outside of the peripheral bank layers 214 a 1, 214 a 2,and 214 a 3, respectively, whereby the multi-layered sealing membrane214 b is formed.

According to the sealing structure in the display device 201 of thepresent embodiment, because a plurality of peripheral bank layers 214 a1, 214 a 2, and 214 a 3 are formed in such a manner that the peripheralbank layers 214 a 2 and 214 a 3 are disposed outside the peripheral banklayer 214 a 1, the flattening resin layers 214 c 1, 214 c 2, and 214 c 3can be reliably blocked even when the flattening resin layers 214 c 1,214 c 2, and 214 c 3 are made thick, whereby the barrier properties ofthe multi-layered sealing membrane 214 b can be further improved. As aresult, it becomes easy to form the multi-layered sealing membrane 214 bby alternately depositing the flattening resin layers 214 c 1, 214 c 2,and 214 c 3 and the barrier layers 214 d 1, 214 d 2, and 214 d 3, andthus the barrier properties against water, oxygen, or the like can befurther improved.

Moreover, because each of the flattening resin layers 214 c 1, 214 c 2,and 214 c 3 are formed inside each of the peripheral bank layers 214 a1, 214 a 2, and 214 a 3, the flattening resin layers can be reliablyblocked by the blocking regions even when a plurality of flatteningresin layers are employed, whereby the barrier properties of themulti-layered sealing membrane can be further improved.

Furthermore, according to the sealing structure in the display device201 of the present embodiment, because each of the barrier layers 214 d1, 214 d 2, and 214 d 3 is formed so as to extend to the outside of eachof the peripheral bank layers 214 a 1, 214 a 2, and 214 a 3, a wide areafor each of the barrier layers can be ensured, whereby adhesion betweenthe multi-layered sealing membrane 214 b and the substrate 2 and thebarrier properties of the multi-layered sealing membrane 214 b can befurther improved, and permeation of water, oxygen, or the like into theelectronic element section can be more effectively prevented.

Next, a method for fabricating the display device 201 according to thepresent embodiment will be explained with reference to FIGS. 14A, 14B,15A, 15B, and 15C. The display device 201 of the present embodiment isfabricated using substantially the same method as for the display device1 of the first embodiment. Note that because the display element sectionin the display device of the present embodiment is made using the samemethod as for the display element section 3 in the display device 1 ofthe first embodiment, the fabrication steps after the display elementsection is made will be explained hereinafter.

FIG. 14A shows a state in which three peripheral bank layers 214 a 1,214 a 2, and 214 a 3 are formed on the inorganic bank layer 112 a. Thesurface of the inorganic bank layer 112 a is made to haveliquid-affinity, and the surfaces of the peripheral bank layers 214 a 1,214 a 2, and 214 a 3 are made liquid-repelling.

As shown in FIG. 14A, as the steps for fabricating the flattening resinlayer, a resin coating substance containing a resin monomer or a resinoligomer is heated and vaporized under vacuum conditions, the vaporizedsubstance is sprayed on the inorganic bank layer 112 b, which isdisposed in the non-display section, and inside the peripheral banklayer 214 a 1, and ultraviolet light is emitted on the sprayed substanceunder vacuum conditions using an ultraviolet lamp, such as a mercurylamp, a metal halide lamp, or the like, so as to polymerize the resinmonomer or the resin oligomer contained in the resin coating substance,and so as to form the flattening resin layer 214 c 1. When the resincoating substance is sprayed, a mask M3 having an opening m3 is disposedabove the substrate 2 while being positioned so that the opening m3 isaligned with the inside portion of the peripheral bank layer 214 aformed on the substrate 2, and the resin coating substance is preferablysprayed through the opening m3. By using the mask M3, the resin coatingsubstance is prevented from being deposited outside the peripheral banklayer 214 a 1. Plasma radiation may be used to polymerize the resinmonomer or the resin oligomer.

The resin coating substance used in this step, which is the same as thatused in the first embodiment, has substantial flowability; however,because the resin coating substance after being sprayed is blocked bythe peripheral bank layer 214 a 1, the resin coating substance cannotflow to the outside of the peripheral bank layer 214 a 1. In thismanner, the flattening resin layer 214 c 1 is formed inside theperipheral bank layer 214 a 1. Note that the thickness of the flatteningresin layer 214 c 1 can be adjusted by the amount of the sprayed resin,and the thickness thereof is preferably set to be, for example, ⅓ to ⅔of the height of the peripheral bank layer 214 a 1.

Next, as shown in FIG. 14B, as the step for fabricating the barrierlayer, the barrier layer 214 d 1 is formed on the flattening resin layer214 c 1 using a vapor deposition process. The barrier layer 214 d 1 maybe formed using, for example, SiO₂, Al₂O₃, or the like, as a vapordeposition material. The vapor deposition process may be the same asthat used in the first embodiment. When the vapor deposition process isperformed, another mask M4 having an opening m4 is preferably disposedabove the substrate 2 while being positioned so that the peripheralportion of the opening m4 is aligned with the outside peripheral portionof the peripheral bank layer 214 a 3 formed on the substrate 2, andvaporized substance is preferably applied and deposited through theopening m4. By using the mask M4, the barrier layer 214 d 1 is preventedfrom being formed on the side edges of the substrate 2. The thickness ofthe barrier layer 214 d 1 is preferably set to be 5 to 500 mm.

Next, as shown in FIG. 15A, as the steps for fabricating anotherflattening resin layer, the resin coating substance is heated andvaporized under vacuum conditions, the vaporized substance is sprayed onthe barrier layer 214 d 1 formed in advance and inside the peripheralbank layers 214 a 1 and 214 a 2, and ultraviolet light is emitted on thesprayed substance under vacuum conditions using an ultraviolet lamp soas to polymerize the resin coating substance, and so as to form theflattening resin layer 214 c 2. When the resin coating substance issprayed, the mask M3 is preferably disposed above the substrate 2 as inthe previous step, and the resin coating substance is preferably sprayedthrough the opening m3. The sprayed resin coating substance flows on thebarrier layer 214 d 1 over the peripheral bank layer 214 a 1, and isblocked by the peripheral bank layer 214 a 2; therefore, the resincoating substance cannot flow to the outside of the peripheral banklayer 214 a 2. In this manner, the flattening resin layer 214 c 2 isformed inside the peripheral bank layers 214 a 1 and 214 a 2. Note thatthe thickness of the flattening resin layer 214 c 2 can be adjusted bythe amount of the sprayed resin, and the thickness thereof is preferablyset to be, for example, ⅓ to ⅔ of the height of the peripheral banklayer 214 a 2.

Next, as shown in FIG. 15B, as the step for fabricating another barrierlayer, the barrier layer 214 d 2 is formed on the flattening resin layer214 c 2 using a vapor deposition process. The barrier layer 214 d 2 maybe formed using, for example, SiO₂, Al₂O₃, or the like, as a vapordeposition material. The vapor deposition process may be the same asthat used in the first embodiment. When the vapor deposition process isperformed, another mask M6 having an opening m6 is preferably disposedabove the substrate 2 while being positioned so that the peripheralportion of the opening m6 is aligned with the outside peripheral portionof the peripheral bank layer 214 a 3 formed on the substrate 2, andvaporized substance is preferably applied and deposited through theopening m6. By using the mask M6, the barrier layer 214 d 2 is preventedfrom being formed on the side edges of the substrate 2. The thickness ofthe barrier layer 214 d 2 is preferably set to be 5 to 500 nm.

Next, as shown in FIG. 15C, by repeating the above-mentioned flatteningresin layer forming step and the barrier layer forming step, theflattening resin layers 214 c 3 and the barrier layer 214 d 3 aresequentially formed on the barrier layer 214 d 2, and thus themulti-layered sealing membrane 214 b is obtained. When the resin coatingsubstance is sprayed for forming the flattening resin layers 214 c 3,the mask M3 is preferably disposed above the substrate 2 as in theprevious step. The sprayed resin coating substance flows on the barrierlayer 214 d 2 over the peripheral bank layers 214 a 1 and 214 a 2, andis blocked by the peripheral bank layer 214 a 3; therefore, the resincoating substance cannot flow to the outside of the peripheral banklayer 214 a 3.

Moreover, when the vapor deposition process is performed for forming thebarrier layer 213 d 3, the mask M6 having the opening m6 is preferablydisposed above the substrate 2 while being positioned so that theperipheral portion of the opening m6 of the mask M6 is aligned with theoutside peripheral portion of the outermost peripheral bank layer 214 a3 formed on the substrate 2, and vaporized substance is preferablyapplied and deposited through the opening. The vapor deposition processis performed in this manner, whereby the barrier layer 214 d 3 isprevented from being formed on the side edges of the substrate 2.

Through the steps explained above, the display device 201 shown in FIG.13 is obtained.

Because the flattening resin layers 214 c 1, 214 c 2, and 214 c 3 areprovided, the barrier layers 214 d 1, 214 d 2, and 214 d 3 can besubstantially made flat, and as a result, the barrier layers 214 d 1,214 d 2, and 214 d 3 can be formed without containing defects such ascracking, pin holes, or the like.

Moreover, because the barrier layers 214 d 1, 214 d 2, and 214 d 3 areformed on the flattening resin layers 214 c 1, 214 c 2, and 214 c 3,adhesions between the flattening resin layers 214 c 1, 214 c 2, and 214c 3 and the barrier layers 214 d 1, 214 d 2, and 214 d 3 are improveddue to anchor effects of the flattening resin layers 214 c 1, 214 c 2,and 214 c 3, and the barrier properties against water and oxygen can beimproved.

Third Embodiment

Next, a third embodiment will be explained below with reference to FIG.16. FIG. 16 is a cross-sectional view showing the major portion of thesealing structure of a display device 301.

The elements of the display device 301 shown in FIG. 16 that are commonto those of the display device 1 of the first embodiment shown in FIGS.1 to 4 will be provided with the same reference symbols, and explanationtherefor will be simplified or omitted.

As shown in FIG. 16, in the display device 301 of the presentembodiment, there are formed a plurality of liquid-repelling regions(blocking regions) 314 a 1, 314 a 2, and 314 a 3 on the peripheral areaof the inorganic bank layer 112 a (of the substrate 2). Morespecifically, the innermost liquid-repelling region is indicated byreference symbol 314 a 1, another liquid-repelling region indicated byreference symbol 314 a 2 is formed outside the liquid-repelling region314 a 1, and a further liquid-repelling region 314 a 3 is formed outsidethe liquid-repelling region 314 a 2. The distances “d” between theliquid-repelling region 314 a 1 and the liquid-repelling region 314 a 2,and between the liquid-repelling region 314 a 2 and the liquid-repellingregion 314 a 3 are preferably set to be 30 to 400 μm.

The liquid-repelling regions 314 a 1, 314 a 2, and 314 a 3 are made byinfiltrating liquid-repelling group such as a fluoro group into thesurface of the inorganic bank layer 112 a by a plasma treatment usingtetrafluoromethane as a reaction gas, as in the case of the organic banklayer 112 b of the first embodiment. As a result, the liquid-repellingregions 314 a 1, 314 a 2, and 314 a 3 function to repel the resincoating substance, which forms the flattening resin layer, and to blockthe flattening resin layer, as the peripheral bank layers 14 a, 214 a 1,etc., in the first and second embodiments.

Moreover, in this display device, there is formed a multi-layeredsealing membrane indicated by reference symbol 314 b. The multi-layeredsealing membrane 314 b is formed by alternately depositing threeflattening resin layers 314 c 1, 314 c 2, and 314 c 3 and three barrierlayers 314 d 1, 314 b 2, and 314 b 3.

The lowermost flattening resin layer 314 c 1, among three flatteningresin layers 314 c 1, 314 c 2, and 314 c 3, is formed on the inorganicbank layer 112 a (liquid-affinitive membrane) in the non-display section11 b and on the display element section (not shown), and is blocked bythe inner side (the left side in FIG. 13) of the innermostliquid-repelling region 314 a 1. Because the surface of the inorganicbank layer 112 a is made to have liquid-affinity, the flattening resinlayer 314 c 1 made of polyacrylic resin or the like is easily settled onthe inorganic bank layer 112 a, and thus adhesion between the inorganicbank layer 112 a and the flattening resin layer 314 c 1 is sufficientlyensured. On the other hand, because the surface of the inorganic banklayer 112 a in the liquid-repelling region 314 a is madeliquid-repelling, the liquid-repelling region 314 a 1 does not acceptthe flattening resin layer 314 c 1, and as a result, the flatteningresin layer 314 c 1 is blocked by the liquid-repelling region 314 a 1.

Next, the barrier layer 314 d 1 is formed on the flattening resin layer314 c 1. The barrier layer 314 d 1 is formed so as to cover theliquid-repelling region 314 a 1, and extends over the liquid-repellingregion 314 a 1 to the outside of the liquid-repelling region 314 a 1 sothat the edge portion 314 e 1 of the barrier layer 314 d 1 is located onthe inorganic bank layer 112 a. In the vicinity of the innermostliquid-repelling region 314 a 1, the flattening resin layer 3141 isblocked by the liquid-repelling region 314 a 1. The barrier layer 314 d1 extends over the flattening resin layer 314 c 1 to reach the outsideof the liquid-repelling region 314 a 1.

Moreover, another flattening resin layer 314 c 2 is formed on thebarrier layer 314 d 1. The flattening resin layer 314 c 2 is formed onthe barrier layer 314 d 1, extends over the innermost liquid-repellingregion 314 a 1, and is blocked by the inner side of the adjacentliquid-repelling region 314 a 2. Because the barrier layer 314 d 1formed in advance is made of SiO₂ or the like, i.e., the surface thereofis made to have liquid-affinity, and because the innermostliquid-repelling region 314 a 1 is covered by the barrier layer 314 d 1,the flattening resin layer 314 c 2 made of polyacrylic resin or the likeis easily settled on the barrier layer 314 d 1, and the flattening resinlayer 314 c 2 extends over liquid-repelling region 314 a 1 to reach theinner side of the adjacent liquid-repelling region 314 a 2.

Next, another barrier layer 314 d 2 is formed on the flattening resinlayer 314 c 2. The barrier layer 314 d 2 is formed so as to cover theliquid-repelling region 314 a 2, and extends over the liquid-repellingregion 314 a 1 to the outside of the liquid-repelling region 314 a 2 sothat the edge portion 314 e 2 of the barrier layer 314 d 2 is located onthe inorganic bank layer 112 a. In the vicinity of the liquid-repellingregion 314 a 2, the flattening resin layer 314 c 2 is blocked by theliquid-repelling region 314 a 2. The barrier layer 314 d 2 extends overthe flattening resin layer 314 c 2 to reach the outside of theliquid-repelling region 314 a 2.

Moreover, a further flattening resin layer 314 c 3 is formed on thebarrier layer 314 d 2. The flattening resin layer 314 c 3 is formed onthe barrier layer 314 d 2, extends over the liquid-repelling regions 314a 1 and 314 a 2, and is blocked by the inner surface of the outermostliquid-repelling region 314 a 3. Because the barrier layer 314 d 2formed in advance is made of SiO₂ or the like, i.e., the surface thereofis made to have liquid-affinity, and because the innermostliquid-repelling region 314 a 2 is covered by the barrier layer 314 d 2,the flattening resin layer 314 c 3 made of polyacrylic resin or the likeis easily settled on the barrier layer 314 d 2, and the flattening resinlayer 314 c 3 extends over liquid-repelling region 314 a 2 to reach theinner side of the adjacent liquid-repelling region 314 a 3.

Next, a further barrier layer 314 d 3 is formed on the flattening resinlayer 314 c 3. The barrier layer 314 d 3 is formed so as to cover theoutermost liquid-repelling region 314 a 3, and extends to the outside ofthe outermost liquid-repelling region 314 a 3 so that the edge portion314 e 3 of the barrier layer 314 d 3 is located on the inorganic banklayer 112 a.

In this manner, in the display device 201 of the present embodiment, aplurality of liquid-repelling regions 314 a 1, 314 a 2, and 314 a 3 areformed, the flattening resin layers 314 c 1, 314 c 2, and 314 c 3 areformed inside the liquid-repelling regions 314 a 1, 314 a 2, and 314 a3, respectively, and the barrier layers 314 d 1, 314 d 2, and 314 d 3extend to the outside of the liquid-repelling regions 314 a 1, 314 a 2,and 314 a 3, respectively, whereby the multi-layered sealing membrane314 b is formed.

According to the sealing structure in the display device 301 of thepresent embodiment, because a plurality of liquid-repelling regions 314a 1, 314 a 2, and 314 a 3 are formed in such a manner that theliquid-repelling regions 314 a 2 and 314 a 3 are disposed outside theliquid-repelling region 314 a 1, the area where the barrier layers 314 d1, 314 d 2, and 314 d 3 are formed can be increased, whereby the barrierproperties of the multi-layered sealing membrane 314 b can be furtherimproved, and permeation of water, oxygen, or the like into the displayelement section 3 can be more effectively prevented. In particular,because the multi-layered sealing membrane 314 b is formed byalternately depositing the flattening resin layers 314 c 1, 314 c 2, and314 c 3 and the barrier layers 314 d 1, 314 d 2, and 314 d 3, thebarrier properties against water, oxygen, or the like can be furtherimproved.

Moreover, because each of the flattening resin layers 314 c 1, 314 c 2,and 314 c 3 are formed inside each of the liquid-repelling regions 314 a1, 314 a 2, and 314 a 3, the barrier properties against water, oxygen,or the like can be further improved, even when a plurality of flatteningresin layers and barrier layers are employed in an alternately depositedmanner.

Furthermore, according to the sealing structure in the display device301 of the present embodiment, a plurality of barrier layers 314 d 1,314 d 2, and 314 d 3 are formed so as to extend to the outside of theliquid-repelling regions 314 a 1, 314 a 2, and 314 a 3, respectively,and the multi-layered sealing membrane 314 b is formed by alternatelydepositing the flattening resin layers 314 c 1, 314 c 2, and 314 c 3 andthe barrier layers 314 d 1, 314 d 2, and 314 d 3; therefore, the barrierproperties against water, oxygen, or the like can be further improved.

In addition, because each of the liquid-repelling regions 314 a 1, 314 a2, and 314 a 3 is formed in a loop-shape, the flattening resin layers314 c 1, 314 c 2, and 314 c 3 are held inside the liquid-repellingregions 314 a 1, 314 a 2, and 314 a 3, respectively; therefore,variation of the barrier properties depending on location can bereduced, and thus reliability of sealing can be improved.

The display device 301 of the present embodiment is fabricated in amanner similar to that for the display device 201 of the secondembodiment except that the liquid-repelling regions 314 a 1, 314 a 2,and 314 a 3 are provided on the peripheral portion of the inorganic banklayer using a plasma treatment, instead of providing the peripheral banklayers. Note that the plasma treatment for the inorganic bank layer 112a and the CF₄ plasma treatment for the organic bank layer may beperformed simultaneously.

Fourth Embodiment

Next, a fourth embodiment will be explained below with reference toFIGS. 17 to 19. FIG. 13 is a schematic plan view showing a displaydevice 401 of the present embodiment, FIG. 18 is a cross-sectional viewtaken along the line A-A′ in FIG. 17, and FIG. 19 is a cross-sectionalview taken along the line B-B′ in FIG. 17.

The elements of the display device 401 shown in FIGS. 17 to 19 that arecommon to those of the display device 1 of the first embodiment shown inFIGS. 1 to 4 will be provided with the same reference symbols, andexplanation therefor will be simplified or omitted.

As shown in FIGS. 17 to 19, in the display device 401, the closed-loopperipheral bank layer 14 a (blocking region) is formed around thedisplay element section 3 disposed on the substrate 2. Moreover,blocking bank layers 414 a (another blocking region) are formed on aflexible tape 130 which is adhered to an end of the substrate 2. Asshown in FIGS. 17 and 19, the blocking bank layers 414 a are formed onboth sides of the flexible tape 130, respectively, while being disposedbetween a control IC 130 a and external terminals 130 b.

Moreover, a multi-layered sealing membrane 414 b is formed on thedisplay element section 3. The multi-layered sealing membrane 414 b isformed by alternately depositing three flattening resin layers 14 c 1,14 c 2, and 414 c 3 and three barrier layers 14 d 1, 14 b 2, and 414 b3. Two flattening resin layers 14 c 1, 14 c 2, among three flatteningresin layers, are formed inside the closed-loop peripheral bank layer 14a, i.e., are blocked by the closed-loop peripheral bank layer 14 a. Twobarrier layers 14 d 1 and 14 b 2, among three barrier layers, are formedon the flattening resin layers 14 c 1 and 14 c 2, respectively (i.e.,inside the peripheral bank layer 14 a), and the edge portions 14 e(i.e., 14 e 1 and 14 e 2) thereof extend over the peripheral bank layer14 a.

The remaining flattening resin layers 414 c 3 is formed so as to coverthe substrate 2, the barrier layer 14 d 2, a portion of the flexibletape 130, and the control IC 130 a, and so as to be disposed in an areacloser to the substrate 2 than from the blocking bank layers 414 a. Theflattening resin layer 414 c 3 is blocked by the blocking bank layers414 a so as not to contact the external terminals 130 b.

Practically, the flattening resin layer 414 c 3 extends to the bottomsurface of the substrate 2, which is not shown in FIGS. 18 and 19.

Moreover, the remaining barrier layer 414 d 3 is formed on theflattening resin layer 414 c 3, and the edge portion 414 e 3 thereofextends over the blocking bank layer 414 a.

The thickness of the blocking bank layer 414 a is preferably set to be 2to 500 μm. The surface of the blocking bank layer 414 a is preferablymade liquid-repelling as in the case of the organic bank layer 112 b orthe peripheral bank layer 14 a.

The flattening resin layer 414 c 3 is made of polyacrylic resin or thelike as the other flattening resin layers 14 c 1 and 14 c 2 to protectthe connecting region between the flexible tape 130 and the substrate 2,and the control IC 130 a. In addition, the flattening resin layer 414 c3 acts to reduce the step coverage of the barrier layer 414 d 3 formedthereon so as to prevent pin holes and cracking from occurring in thebarrier layer 414 d 3. The barrier layer 414 d 3 consists of aninorganic membrane such as SiO₂ or the like as the other barrier layers14 d 1 and 14 d 2 so as to be superior in blocking water or oxygen. Themulti-layered sealing membrane 414 b is formed by alternately depositingthe flattening resin layers 14 c 1, 14 c 2, and 414 c 3 and the barrierlayers 14 d 1, 14 b 2, and 414 b 3 in order to protect the displayelement section 3, the connecting region between the flexible tape 130and the substrate 2, and the control IC 130 a from permeation of wateror oxygen.

The sealing structure will be described more specifically. As shown inFIGS. 18 and 19, the flattening resin layer 414 c 3 is formed on thebarrier layer 14 d 2, on the substrate 2, on both sides of the flexibletape 130, and on the control IC 130 a, and is blocked by the blockingbank layer 414 a. In other words, the thickness of the flattening resinlayer 414 c 3 is set to be equal to or less than that of the blockingbank layer 414 a.

The barrier layer 414 d 3 is deposited on the flattening resin layer 414c 3. The barrier layer 414 d 3 is formed so as to cover the blockingbank layer 414 a, and extends over the blocking bank layer 414 a to aposition adjacent to the external terminal 130 b.

The blocking bank layer 414 a is made of a resist having thermalresistance and solvent resistance, such as acrylic resin, polyimideresin, or the like, as mentioned above. The thickness of the blockingbank layer 414 a is preferably set to be 2 to 600 μm. The thickness ofthe blocking bank layer 414 a depends on the thickness of layers such asthe resist for forming the flexible tape, patterned wirings, markings,or the like when such layers are also used as the blocking bank layer414 a. Alternatively, the blocking bank layer 414 a may be formed so asto have a predetermined thickness using an ink-jet method.

The flattening resin layer 414 c 3 is made of acrylic resin or the like.The thickness of the flattening resin layer 414 c 3 is preferably set tobe 0.1 to 10 μm. The thickness of the flattening resin layer 414 c 3 ispreferably adjusted depending on the irregularities on the flexibletape.

The barrier layer 414 d 3 is made of metal such as aluminum, titanium,or the like, or oxide such as SiO₂, Al₂O₃, or the like. The thickness ofthe barrier layer 414 d 3 is preferably set to be 10 to 1000 nm. Thethickness of the barrier layer 414 d 3 is preferably adjusted dependingon use, or required barrier properties.

By employing such a sealing structure, the entire drive circuitincluding the drive IC 130 a is encapsulated by the flattening resinlayer 414 c 3 and the barrier layer 414 d 3; therefore, permeation ofwater or oxygen into the connecting portion between the drive circuitand the display section, which is susceptible to humidity, can beprevented, and reliability of the overall display device can be furtherimproved.

Fifth Embodiment

Next, specific examples of electronic apparatus comprising one of thedisplay devices according to the first to fourth embodiments will beexplained below.

FIG. 20A is a perspective view of an example of a portable telephone ora remote controller. In FIG. 20A, reference symbol 600 indicates a bodyof the portable telephone and reference symbol 601 indicates a displayportion comprising any one of the display devices 1, 201, 301, and 401described above.

FIG. 20B is a perspective view of an example of a portable informationprocessor such as a PDA or a personal computer. In FIG. 20B, referencesymbol 700 indicates an information processor, reference symbol 701indicates an input device such as a keyboard, reference symbol 703indicates a body of the information processor, and reference symbol 702indicates a display portion comprising any one of the display devices 1,201, 301, and 401 described above.

FIG. 20C is a perspective view of an example of a watch. In FIG. 20C,reference symbol 800 indicates a body of the watch and reference symbol801 indicates a display portion comprising any one of the displaydevices 1, 201, 301, and 401 described above.

Each of the electronic apparatuses shown in FIGS. 20A to 20C includes adisplay portion comprising any one of the display devices 1, 201, 301,and 401 described above, and thus has the same advantages as that of thedisplay devices according to the first to fifth embodiments; therefore,these electronic apparatuses will exhibit an excellent displayperformance while being thin.

The electronic apparatus may be fabricated through the steps offabricating, in a manner similar to that for the first to fifthembodiments, one the display devices 1, 201, 301, and 401 including thedrive IC 130 a shown in FIG. 2, incorporating one of the display devices1, 201, 301, and 401 into an electronic apparatus such as a portabletelephone, an information processor, or watch.

The present invention is not limited to the embodiments explained above,and various modifications may be made without departing from the scopeof the present invention.

For example, the display devices of the present invention may be made insuch a manner that a plurality of display element sections 3 are formedon a mother substrate 2A, and the mother substrate 2A is divided intothe display element sections 3, whereby a number of display devices canbe obtained at a time. In this case, as shown in FIG. 21, a mask Mhaving a plurality of openings “m” corresponding to the display elementsections 3 may preferably be used when a resin coating substance issprayed. The openings “m” of the mask M are formed so as not to exposecutting lines 2B drawn on the mother substrate 2A for each of thedisplay devices. As a result, the flattening resin layers and barrierlayers are not formed on the cutting lines 2B; therefore, the flatteningresin layers may not be separated when the mother substrate 2A is cut.

In the above description, the blocking regions and the organic banklayers are made of the same material and are formed in the samefabrication step; however, in the case of passive organic EL devices, aresist or a marking on a cathode separator or a circuit boardcorresponds to the blocking region, and such elements which have ablocking function, and which are formed in existing fabrication steps,may preferably be used as the blocking regions.

INDUSTRIAL APPLICABILITY

As explained above in detail, according to the sealing structure in thedisplay device of the present invention, specific sections including thedisplay element sections can be selectively and reliably sealed by themulti-layered sealing structure formed by depositing the flatteningresin layers and barrier layers, and the multi-layered sealing structurecan be made thinner than a “sealing can” in a conventional sealingstructure even when sealing areas are large; therefore, the overallthickness of the display device can be greatly reduced from conventionaldisplay devices.

In addition, the positions of the edges of the multi-layered sealingstructure, which is formed by the flattening resin layer and the barrierlayer that is free from pin holes, cracking, and thickness variation dueto the flattening resin layer, can be accurately defined by the blockingregions. Moreover, adhesion of the edges of the multi-layered sealingstructure is improved by ensuring a large contact area between thesubstrate whose surface is made to have liquid-affinity and themulti-layered sealing structure, the permeation passes against water,oxygen, impurity ions, or the like can be made long due toirregularities of the blocking region; therefore, excellent barrierproperties and reliability of the sealing structure can be maintained ina long period even when the blocking region is narrow.

As a result, the frame region of an organic EL display device or of aLCD can be made narrower than that of a conventional display device,while decreasing the thickness and weight of the display device, wherebyelectronic apparatuses can be obtained in which freedom of exteriordesign is enhanced and spaces are effectively utilized. In addition,because unusable area due to the frame region is decreased, the numberof display devices that are obtainable from a mother substrate may beincreased, and productivity may be improved.

Furthermore, the sealing structure can be broadly applicable to anelectronic apparatus, electrical apparatus, a module, and componentssuch as a circuit board having a number of elements, an electron-opticalmodule, an IC card, or the like, as a sealing means which has anintegral structure and flexibility, and which is thin and lightweight.

1. A display device comprising: a base member; an electronic elementdisposed above the base member, the electronic element including: apixel electrode disposed above the base member, the pixel electrodebeing formed in a display section; a cathode electrode opposing to thepixel electrode; and a luminescent layer that is provided between thepixel electrode and the cathode electrode; a cathode line disposedoutside the display section, the cathode line being connected to thecathode electrode at a connecting region; a sealing structure for theelectronic element, the sealing structure including: a first blockingregion disposed outside the display section; a first resin layer that isformed above the base member and that is delineated by the firstblocking region formed on the base member; and a first barrier layerextending beyond the first resin layer to cover the first blockingregion; a second resin layer disposed over the first barrier layer andthat is delineated by the first blocking region; and a second barrierlayer covering the second resin layer and the first blocking region,wherein the connecting region is disposed between the first blockingregion and the display section.
 2. A display device according to claim1, wherein the first blocking region surrounds at least the displaysection.
 3. An electronic apparatus comprising the display deviceaccording to claim
 1. 4. A display device comprising: a base member; anelectronic element disposed above the base member, the electronicelement including: a pixel electrode disposed above the base member, thepixel electrode being formed in a display section; a cathode electrodeopposing to the pixel electrode; and a luminescent layer that isprovided between the pixel electrode and the cathode electrode; acathode line disposed outside the display section, the cathode linebeing connected to the cathode electrode at a connecting region; asealing structure for the electronic element, the sealing structureincluding: a first blocking region disposed outside the display section;a first resin layer that is formed above the base member and that isdelineated by the first blocking region formed on the base member; and afirst barrier layer extending beyond the first resin layer to cover thefirst blocking region; a second blocking region disposed outside thefirst blocking region; a second resin layer disposed over the firstbarrier layer, and delineated by the second blocking region; and asecond barrier layer extending beyond the second resin layer to coverthe first blocking region and the second blocking region, wherein theconnecting region is disposed between the first blocking region and thedisplay section.
 5. A display device according to claim 4, furthercomprising a flexible tape adhered to an end of the base member, whereinthe second blocking region is disposed on the flexible tape.
 6. Adisplay device according to claim 5, further comprising a control ICdisposed on the flexible tape, wherein the second blocking region, thesecond resin layer, and the second barrier layer are formed on bothsides of the flexible tape, and wherein the control IC is covered by thesecond resin layer.
 7. A display device according to claim 4, whereinthe first blocking region surrounds at least the display section.
 8. Anelectronic apparatus comprising the display device according to claim 4.